package com.zbar.decode;

import android.app.Activity;
import android.content.Intent;
import android.os.Handler;
import android.os.Message;
import android.util.Log;

import com.zbar.R;
import com.zbar.camera.CameraManager;
import com.zbar.client.CaptureActivity;
/**
 * This class handles all the messaging which comprises the state machine for capture.
 */
public final class CaptureActivityHandler extends Handler {

	private static final String TAG = CaptureActivityHandler.class.getSimpleName();

	private final CaptureActivity activity;
	private final DecodeThread decodeThread;
	private State state;

	private enum State {
		PREVIEW, SUCCESS, DONE
	}

	public CaptureActivityHandler(CaptureActivity activity) {
		this.activity = activity;
		decodeThread = new DecodeThread(activity);
		decodeThread.start();
		state = State.SUCCESS;
		CameraManager.get().startPreview();
		restartPreviewAndDecode();
	}

	@Override
	public void handleMessage(Message message) {
		if (message.what == R.id.auto_focus) {
			if (state == State.PREVIEW) {
				CameraManager.get().requestAutoFocus(this, R.id.auto_focus);
			}
		} else if (message.what == R.id.restart_preview) {
			Log.d(TAG, "Got restart preview message");
			restartPreviewAndDecode();
		} else if (message.what == R.id.decode_succeeded) {
			String strResult = (String) message.obj;
			Log.d(TAG, "Got decode succeeded message:" + strResult);
			state = State.SUCCESS;
			activity.handleDecode(strResult);
		} else if (message.what == R.id.decode_failed) {
			state = State.PREVIEW;
			CameraManager.get().requestPreviewFrame(decodeThread.getHandler(), R.id.decode);
		} else if (message.what == R.id.return_scan_result) {
			Log.d(TAG, "Got return scan result message");
			activity.setResult(Activity.RESULT_OK, (Intent) message.obj);
			activity.finish();
		}
	}

	public void quitSynchronously() {
		state = State.DONE;
		CameraManager.get().stopPreview();
		Message quit = Message.obtain(decodeThread.getHandler(), R.id.quit);
		quit.sendToTarget();
		try {
			decodeThread.join();
		} catch (InterruptedException e) {
			// continue
		}
		removeMessages(R.id.decode_succeeded);
		removeMessages(R.id.decode_failed);
	}

	private void restartPreviewAndDecode() {
		if (state == State.SUCCESS) {
			state = State.PREVIEW;
			CameraManager.get().requestPreviewFrame(decodeThread.getHandler(), R.id.decode);
			CameraManager.get().requestAutoFocus(this, R.id.auto_focus);
			activity.drawViewfinder();
		}
	}

}
